Thermal Gas Flow Meter Transient Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flow rate measuring devices face challenges in accurately measuring fluid flow rates due to dependence on physical properties such as thermal diffusion, especially when dealing with fluids of similar composition or type, leading to inaccuracies in measurement.
Innovation Solution
A flow rate measuring device that includes a heater, a temperature detector, and a flow rate correcting unit which corrects the flow rate based on the change tendency of the detected temperature over time, using transient periods and slopes to reduce the influence of physical properties affecting thermal diffusion, and is arranged with multiple temperature detectors to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If physical property value detectors are arranged side by side in the direction orthogonal to the flow direction to cope with flow rate dependence, then the measurement can handle different flow rates, but the flow rate dependence cannot be reduced when the fluid is similar in composition or type
Solution Approach 1:
The patent changes the parameter used for flow rate correction from steady-state physical property values to transient response characteristics. By measuring how the detection value changes over time from the start of heating (specifically the transient period until reaching a predetermined percentage of thermal equilibrium temperature), the system captures dynamic thermal diffusion behavior that varies with flow rate but is independent of fluid composition, thereby resolving the contradiction between adaptability and precision
2Device complexity
If correction is based on steady-state thermal equilibrium temperature, then the measurement is simple, but the flow rate dependence on physical properties of similar fluids cannot be reduced
Solution Approach 1:
The patent applies preliminary action by measuring the transient response characteristics during the heating process before thermal equilibrium is reached. By capturing the dynamic change tendency of the detection value during the transient period (rather than waiting for steady state), the system obtains flow rate information that is independent of fluid composition, thus improving precision without significantly increasing complexity
Solution Approach 2:
The patent uses periodic heating and cooling cycles to measure transient response characteristics. By repeatedly applying heat and observing the transient temperature变化 over time, the system can accurately determine flow rate based on the dynamic response pattern, which varies with flow rate but not with fluid composition, thereby resolving the contradiction between simplicity and precision
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves higher accuracy in measuring fluid flow rates by minimizing the impact of physical properties, providing a more reliable and precise measurement of flow rates, even for fluids of similar composition.
Implementation Method 1
a heater (113) configured to heat a fluid
Implementation Method 2
a temperature detector (111, 112) configured to detect a temperature of the fluid
Implementation Method 3
the influence of physical properties affecting thermal diffusion of a fluid similar in composition or type
Data Source
AI summary
Provided are a heater that heats a fluid, and a temperature detector that detects a temperature of the fluid, and a flow rate of the fluid flowing through a main channel is corrected based on a tendency of a detection value detected by the temperature detector to change over time.